Synthesis and Properties of Functional π-Expanded Compounds Prepared by Thermal or Photochemical Conversion of the Precursors

Abstract

This paper focuses on the synthesis of new aromatic compounds by thermal, photochemical, or oxidative cleavage reaction of the corresponding precursors. The precursor-methods are useful for the derivatization of the non-soluble aromatic compounds. We have applied retro Diels-Alder reactions for the preparation of new π-expanded porphyrinoid compounds such as [14]tribenzotriphyrin(2.1.1), tetrabenzoporphycene, dodecasubstituted porphycene, tetraanthraporphyin, butadiyne-linked tetrabenzoporphyrin dimer, and so on. We have investigated the photocleavage synthesis of pentacenes from the corresponding α-diketone precursors. This photoreaction enabled us to prepare 1,4,8,11-tetrasubstituted pentacene. The synthesis of new pentacene derivatives with electron-withdrawing substituents at 6,13-positions by oxidative cleavage reaction will be also reported.